<html>
<!-- <script>
   //普通的while循环 打印出1~10的数
   var count = 0;
   while (count<10) {
       console.log(count);
       count++;
   }
    
</script> -->

<!-- <script>
    //do/while循环 打印出1~10的数
    var count = 0;
    while (count<10) {
        console.log(count);
        count++;
    }
 </script> -->

<!-- <script>
     // 根据参数a的长度打印出1~a的长度
    function printArray(a) {
        var len = a.length, i = 0;
        if(len == 0){
            console.log("Empty Array");
        } else {
            do{
                console.log(a[i]);
            } while (++i < len); 
        }
    }
    printArray([]);
 </script> -->

<script>
    // for in循环
    var o = { x: 1, y: 2, z: 3 };
    var a = [], i = 0;
    for (b in o) {
        console.log(b)
    }

</script>

<head>
    <title>放置文章标题</title>
</head>

<body>
    <!-- <div>
            <h1>Debug Log</h1>
    </div> -->
</body>

</html>